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llvm-mirror/lib/Option/OptTable.cpp
Nico Weber c68fbdca33 Option spell checking: Penalize delimiter flags if input has no argument
If the user passes a flag like `-version` to a program, it's more likely
they mean `--version` than `-version:`, since there's no parameter
passed. Hence, give delimited arguments a penalty of 1 if the user input
doesn't contain the delimiter or no data after it.

The motivation is that with this, lld-link can suggest "--version"
instead of "-version:" for "-version" and "-nodefaultlib" instead of
"-nodefaultlib:" for "-nodefaultlibs".

Differential Revision: https://reviews.llvm.org/D61382

llvm-svn: 359701
2019-05-01 16:45:15 +00:00

584 lines
19 KiB
C++

//===- OptTable.cpp - Option Table Implementation -------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/ADT/StringSet.h"
#include "llvm/Option/Arg.h"
#include "llvm/Option/ArgList.h"
#include "llvm/Option/Option.h"
#include "llvm/Option/OptSpecifier.h"
#include "llvm/Option/OptTable.h"
#include "llvm/Support/Compiler.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/raw_ostream.h"
#include <algorithm>
#include <cassert>
#include <cctype>
#include <cstring>
#include <map>
#include <string>
#include <utility>
#include <vector>
using namespace llvm;
using namespace llvm::opt;
namespace llvm {
namespace opt {
// Ordering on Info. The ordering is *almost* case-insensitive lexicographic,
// with an exception. '\0' comes at the end of the alphabet instead of the
// beginning (thus options precede any other options which prefix them).
static int StrCmpOptionNameIgnoreCase(const char *A, const char *B) {
const char *X = A, *Y = B;
char a = tolower(*A), b = tolower(*B);
while (a == b) {
if (a == '\0')
return 0;
a = tolower(*++X);
b = tolower(*++Y);
}
if (a == '\0') // A is a prefix of B.
return 1;
if (b == '\0') // B is a prefix of A.
return -1;
// Otherwise lexicographic.
return (a < b) ? -1 : 1;
}
#ifndef NDEBUG
static int StrCmpOptionName(const char *A, const char *B) {
if (int N = StrCmpOptionNameIgnoreCase(A, B))
return N;
return strcmp(A, B);
}
static inline bool operator<(const OptTable::Info &A, const OptTable::Info &B) {
if (&A == &B)
return false;
if (int N = StrCmpOptionName(A.Name, B.Name))
return N < 0;
for (const char * const *APre = A.Prefixes,
* const *BPre = B.Prefixes;
*APre != nullptr && *BPre != nullptr; ++APre, ++BPre){
if (int N = StrCmpOptionName(*APre, *BPre))
return N < 0;
}
// Names are the same, check that classes are in order; exactly one
// should be joined, and it should succeed the other.
assert(((A.Kind == Option::JoinedClass) ^ (B.Kind == Option::JoinedClass)) &&
"Unexpected classes for options with same name.");
return B.Kind == Option::JoinedClass;
}
#endif
// Support lower_bound between info and an option name.
static inline bool operator<(const OptTable::Info &I, const char *Name) {
return StrCmpOptionNameIgnoreCase(I.Name, Name) < 0;
}
} // end namespace opt
} // end namespace llvm
OptSpecifier::OptSpecifier(const Option *Opt) : ID(Opt->getID()) {}
OptTable::OptTable(ArrayRef<Info> OptionInfos, bool IgnoreCase)
: OptionInfos(OptionInfos), IgnoreCase(IgnoreCase) {
// Explicitly zero initialize the error to work around a bug in array
// value-initialization on MinGW with gcc 4.3.5.
// Find start of normal options.
for (unsigned i = 0, e = getNumOptions(); i != e; ++i) {
unsigned Kind = getInfo(i + 1).Kind;
if (Kind == Option::InputClass) {
assert(!TheInputOptionID && "Cannot have multiple input options!");
TheInputOptionID = getInfo(i + 1).ID;
} else if (Kind == Option::UnknownClass) {
assert(!TheUnknownOptionID && "Cannot have multiple unknown options!");
TheUnknownOptionID = getInfo(i + 1).ID;
} else if (Kind != Option::GroupClass) {
FirstSearchableIndex = i;
break;
}
}
assert(FirstSearchableIndex != 0 && "No searchable options?");
#ifndef NDEBUG
// Check that everything after the first searchable option is a
// regular option class.
for (unsigned i = FirstSearchableIndex, e = getNumOptions(); i != e; ++i) {
Option::OptionClass Kind = (Option::OptionClass) getInfo(i + 1).Kind;
assert((Kind != Option::InputClass && Kind != Option::UnknownClass &&
Kind != Option::GroupClass) &&
"Special options should be defined first!");
}
// Check that options are in order.
for (unsigned i = FirstSearchableIndex + 1, e = getNumOptions(); i != e; ++i){
if (!(getInfo(i) < getInfo(i + 1))) {
getOption(i).dump();
getOption(i + 1).dump();
llvm_unreachable("Options are not in order!");
}
}
#endif
// Build prefixes.
for (unsigned i = FirstSearchableIndex + 1, e = getNumOptions() + 1;
i != e; ++i) {
if (const char *const *P = getInfo(i).Prefixes) {
for (; *P != nullptr; ++P) {
PrefixesUnion.insert(*P);
}
}
}
// Build prefix chars.
for (StringSet<>::const_iterator I = PrefixesUnion.begin(),
E = PrefixesUnion.end(); I != E; ++I) {
StringRef Prefix = I->getKey();
for (StringRef::const_iterator C = Prefix.begin(), CE = Prefix.end();
C != CE; ++C)
if (!is_contained(PrefixChars, *C))
PrefixChars.push_back(*C);
}
}
OptTable::~OptTable() = default;
const Option OptTable::getOption(OptSpecifier Opt) const {
unsigned id = Opt.getID();
if (id == 0)
return Option(nullptr, nullptr);
assert((unsigned) (id - 1) < getNumOptions() && "Invalid ID.");
return Option(&getInfo(id), this);
}
static bool isInput(const StringSet<> &Prefixes, StringRef Arg) {
if (Arg == "-")
return true;
for (StringSet<>::const_iterator I = Prefixes.begin(),
E = Prefixes.end(); I != E; ++I)
if (Arg.startswith(I->getKey()))
return false;
return true;
}
/// \returns Matched size. 0 means no match.
static unsigned matchOption(const OptTable::Info *I, StringRef Str,
bool IgnoreCase) {
for (const char * const *Pre = I->Prefixes; *Pre != nullptr; ++Pre) {
StringRef Prefix(*Pre);
if (Str.startswith(Prefix)) {
StringRef Rest = Str.substr(Prefix.size());
bool Matched = IgnoreCase
? Rest.startswith_lower(I->Name)
: Rest.startswith(I->Name);
if (Matched)
return Prefix.size() + StringRef(I->Name).size();
}
}
return 0;
}
// Returns true if one of the Prefixes + In.Names matches Option
static bool optionMatches(const OptTable::Info &In, StringRef Option) {
if (In.Prefixes)
for (size_t I = 0; In.Prefixes[I]; I++)
if (Option == std::string(In.Prefixes[I]) + In.Name)
return true;
return false;
}
// This function is for flag value completion.
// Eg. When "-stdlib=" and "l" was passed to this function, it will return
// appropiriate values for stdlib, which starts with l.
std::vector<std::string>
OptTable::suggestValueCompletions(StringRef Option, StringRef Arg) const {
// Search all options and return possible values.
for (size_t I = FirstSearchableIndex, E = OptionInfos.size(); I < E; I++) {
const Info &In = OptionInfos[I];
if (!In.Values || !optionMatches(In, Option))
continue;
SmallVector<StringRef, 8> Candidates;
StringRef(In.Values).split(Candidates, ",", -1, false);
std::vector<std::string> Result;
for (StringRef Val : Candidates)
if (Val.startswith(Arg) && Arg.compare(Val))
Result.push_back(Val);
return Result;
}
return {};
}
std::vector<std::string>
OptTable::findByPrefix(StringRef Cur, unsigned short DisableFlags) const {
std::vector<std::string> Ret;
for (size_t I = FirstSearchableIndex, E = OptionInfos.size(); I < E; I++) {
const Info &In = OptionInfos[I];
if (!In.Prefixes || (!In.HelpText && !In.GroupID))
continue;
if (In.Flags & DisableFlags)
continue;
for (int I = 0; In.Prefixes[I]; I++) {
std::string S = std::string(In.Prefixes[I]) + std::string(In.Name) + "\t";
if (In.HelpText)
S += In.HelpText;
if (StringRef(S).startswith(Cur) && S.compare(std::string(Cur) + "\t"))
Ret.push_back(S);
}
}
return Ret;
}
unsigned OptTable::findNearest(StringRef Option, std::string &NearestString,
unsigned FlagsToInclude, unsigned FlagsToExclude,
unsigned MinimumLength) const {
assert(!Option.empty());
// Consider each [option prefix + option name] pair as a candidate, finding
// the closest match.
unsigned BestDistance = UINT_MAX;
for (const Info &CandidateInfo :
ArrayRef<Info>(OptionInfos).drop_front(FirstSearchableIndex)) {
StringRef CandidateName = CandidateInfo.Name;
// We can eliminate some option prefix/name pairs as candidates right away:
// * Ignore option candidates with empty names, such as "--", or names
// that do not meet the minimum length.
if (CandidateName.empty() || CandidateName.size() < MinimumLength)
continue;
// * If FlagsToInclude were specified, ignore options that don't include
// those flags.
if (FlagsToInclude && !(CandidateInfo.Flags & FlagsToInclude))
continue;
// * Ignore options that contain the FlagsToExclude.
if (CandidateInfo.Flags & FlagsToExclude)
continue;
// * Ignore positional argument option candidates (which do not
// have prefixes).
if (!CandidateInfo.Prefixes)
continue;
// Now check if the candidate ends with a character commonly used when
// delimiting an option from its value, such as '=' or ':'. If it does,
// attempt to split the given option based on that delimiter.
StringRef LHS, RHS;
char Last = CandidateName.back();
bool CandidateHasDelimiter = Last == '=' || Last == ':';
std::string NormalizedName = Option;
if (CandidateHasDelimiter) {
std::tie(LHS, RHS) = Option.split(Last);
NormalizedName = LHS;
if (Option.find(Last) == LHS.size())
NormalizedName += Last;
}
// Consider each possible prefix for each candidate to find the most
// appropriate one. For example, if a user asks for "--helm", suggest
// "--help" over "-help".
for (int P = 0;
const char *const CandidatePrefix = CandidateInfo.Prefixes[P]; P++) {
std::string Candidate = (CandidatePrefix + CandidateName).str();
StringRef CandidateRef = Candidate;
unsigned Distance =
CandidateRef.edit_distance(NormalizedName, /*AllowReplacements=*/true,
/*MaxEditDistance=*/BestDistance);
if (RHS.empty() && CandidateHasDelimiter) {
// The Candidate ends with a = or : delimiter, but the option passed in
// didn't contain the delimiter (or doesn't have anything after it).
// In that case, penalize the correction: `-nodefaultlibs` is more
// likely to be a spello for `-nodefaultlib` than `-nodefaultlib:` even
// though both have an unmodified editing distance of 1, since the
// latter would need an argument.
++Distance;
}
if (Distance < BestDistance) {
BestDistance = Distance;
NearestString = (Candidate + RHS).str();
}
}
}
return BestDistance;
}
bool OptTable::addValues(const char *Option, const char *Values) {
for (size_t I = FirstSearchableIndex, E = OptionInfos.size(); I < E; I++) {
Info &In = OptionInfos[I];
if (optionMatches(In, Option)) {
In.Values = Values;
return true;
}
}
return false;
}
Arg *OptTable::ParseOneArg(const ArgList &Args, unsigned &Index,
unsigned FlagsToInclude,
unsigned FlagsToExclude) const {
unsigned Prev = Index;
const char *Str = Args.getArgString(Index);
// Anything that doesn't start with PrefixesUnion is an input, as is '-'
// itself.
if (isInput(PrefixesUnion, Str))
return new Arg(getOption(TheInputOptionID), Str, Index++, Str);
const Info *Start = OptionInfos.data() + FirstSearchableIndex;
const Info *End = OptionInfos.data() + OptionInfos.size();
StringRef Name = StringRef(Str).ltrim(PrefixChars);
// Search for the first next option which could be a prefix.
Start = std::lower_bound(Start, End, Name.data());
// Options are stored in sorted order, with '\0' at the end of the
// alphabet. Since the only options which can accept a string must
// prefix it, we iteratively search for the next option which could
// be a prefix.
//
// FIXME: This is searching much more than necessary, but I am
// blanking on the simplest way to make it fast. We can solve this
// problem when we move to TableGen.
for (; Start != End; ++Start) {
unsigned ArgSize = 0;
// Scan for first option which is a proper prefix.
for (; Start != End; ++Start)
if ((ArgSize = matchOption(Start, Str, IgnoreCase)))
break;
if (Start == End)
break;
Option Opt(Start, this);
if (FlagsToInclude && !Opt.hasFlag(FlagsToInclude))
continue;
if (Opt.hasFlag(FlagsToExclude))
continue;
// See if this option matches.
if (Arg *A = Opt.accept(Args, Index, ArgSize))
return A;
// Otherwise, see if this argument was missing values.
if (Prev != Index)
return nullptr;
}
// If we failed to find an option and this arg started with /, then it's
// probably an input path.
if (Str[0] == '/')
return new Arg(getOption(TheInputOptionID), Str, Index++, Str);
return new Arg(getOption(TheUnknownOptionID), Str, Index++, Str);
}
InputArgList OptTable::ParseArgs(ArrayRef<const char *> ArgArr,
unsigned &MissingArgIndex,
unsigned &MissingArgCount,
unsigned FlagsToInclude,
unsigned FlagsToExclude) const {
InputArgList Args(ArgArr.begin(), ArgArr.end());
// FIXME: Handle '@' args (or at least error on them).
MissingArgIndex = MissingArgCount = 0;
unsigned Index = 0, End = ArgArr.size();
while (Index < End) {
// Ingore nullptrs, they are response file's EOL markers
if (Args.getArgString(Index) == nullptr) {
++Index;
continue;
}
// Ignore empty arguments (other things may still take them as arguments).
StringRef Str = Args.getArgString(Index);
if (Str == "") {
++Index;
continue;
}
unsigned Prev = Index;
Arg *A = ParseOneArg(Args, Index, FlagsToInclude, FlagsToExclude);
assert(Index > Prev && "Parser failed to consume argument.");
// Check for missing argument error.
if (!A) {
assert(Index >= End && "Unexpected parser error.");
assert(Index - Prev - 1 && "No missing arguments!");
MissingArgIndex = Prev;
MissingArgCount = Index - Prev - 1;
break;
}
Args.append(A);
}
return Args;
}
static std::string getOptionHelpName(const OptTable &Opts, OptSpecifier Id) {
const Option O = Opts.getOption(Id);
std::string Name = O.getPrefixedName();
// Add metavar, if used.
switch (O.getKind()) {
case Option::GroupClass: case Option::InputClass: case Option::UnknownClass:
llvm_unreachable("Invalid option with help text.");
case Option::MultiArgClass:
if (const char *MetaVarName = Opts.getOptionMetaVar(Id)) {
// For MultiArgs, metavar is full list of all argument names.
Name += ' ';
Name += MetaVarName;
}
else {
// For MultiArgs<N>, if metavar not supplied, print <value> N times.
for (unsigned i=0, e=O.getNumArgs(); i< e; ++i) {
Name += " <value>";
}
}
break;
case Option::FlagClass:
break;
case Option::ValuesClass:
break;
case Option::SeparateClass: case Option::JoinedOrSeparateClass:
case Option::RemainingArgsClass: case Option::RemainingArgsJoinedClass:
Name += ' ';
LLVM_FALLTHROUGH;
case Option::JoinedClass: case Option::CommaJoinedClass:
case Option::JoinedAndSeparateClass:
if (const char *MetaVarName = Opts.getOptionMetaVar(Id))
Name += MetaVarName;
else
Name += "<value>";
break;
}
return Name;
}
namespace {
struct OptionInfo {
std::string Name;
StringRef HelpText;
};
} // namespace
static void PrintHelpOptionList(raw_ostream &OS, StringRef Title,
std::vector<OptionInfo> &OptionHelp) {
OS << Title << ":\n";
// Find the maximum option length.
unsigned OptionFieldWidth = 0;
for (unsigned i = 0, e = OptionHelp.size(); i != e; ++i) {
// Limit the amount of padding we are willing to give up for alignment.
unsigned Length = OptionHelp[i].Name.size();
if (Length <= 23)
OptionFieldWidth = std::max(OptionFieldWidth, Length);
}
const unsigned InitialPad = 2;
for (unsigned i = 0, e = OptionHelp.size(); i != e; ++i) {
const std::string &Option = OptionHelp[i].Name;
int Pad = OptionFieldWidth - int(Option.size());
OS.indent(InitialPad) << Option;
// Break on long option names.
if (Pad < 0) {
OS << "\n";
Pad = OptionFieldWidth + InitialPad;
}
OS.indent(Pad + 1) << OptionHelp[i].HelpText << '\n';
}
}
static const char *getOptionHelpGroup(const OptTable &Opts, OptSpecifier Id) {
unsigned GroupID = Opts.getOptionGroupID(Id);
// If not in a group, return the default help group.
if (!GroupID)
return "OPTIONS";
// Abuse the help text of the option groups to store the "help group"
// name.
//
// FIXME: Split out option groups.
if (const char *GroupHelp = Opts.getOptionHelpText(GroupID))
return GroupHelp;
// Otherwise keep looking.
return getOptionHelpGroup(Opts, GroupID);
}
void OptTable::PrintHelp(raw_ostream &OS, const char *Usage, const char *Title,
bool ShowHidden, bool ShowAllAliases) const {
PrintHelp(OS, Usage, Title, /*Include*/ 0, /*Exclude*/
(ShowHidden ? 0 : HelpHidden), ShowAllAliases);
}
void OptTable::PrintHelp(raw_ostream &OS, const char *Usage, const char *Title,
unsigned FlagsToInclude, unsigned FlagsToExclude,
bool ShowAllAliases) const {
OS << "OVERVIEW: " << Title << "\n\n";
OS << "USAGE: " << Usage << "\n\n";
// Render help text into a map of group-name to a list of (option, help)
// pairs.
std::map<std::string, std::vector<OptionInfo>> GroupedOptionHelp;
for (unsigned Id = 1, e = getNumOptions() + 1; Id != e; ++Id) {
// FIXME: Split out option groups.
if (getOptionKind(Id) == Option::GroupClass)
continue;
unsigned Flags = getInfo(Id).Flags;
if (FlagsToInclude && !(Flags & FlagsToInclude))
continue;
if (Flags & FlagsToExclude)
continue;
// If an alias doesn't have a help text, show a help text for the aliased
// option instead.
const char *HelpText = getOptionHelpText(Id);
if (!HelpText && ShowAllAliases) {
const Option Alias = getOption(Id).getAlias();
if (Alias.isValid())
HelpText = getOptionHelpText(Alias.getID());
}
if (HelpText) {
const char *HelpGroup = getOptionHelpGroup(*this, Id);
const std::string &OptName = getOptionHelpName(*this, Id);
GroupedOptionHelp[HelpGroup].push_back({OptName, HelpText});
}
}
for (auto& OptionGroup : GroupedOptionHelp) {
if (OptionGroup.first != GroupedOptionHelp.begin()->first)
OS << "\n";
PrintHelpOptionList(OS, OptionGroup.first, OptionGroup.second);
}
OS.flush();
}